Microelectromechanical systems, or MEMS-based devices, can be used in a variety of applications, such as accelerometers, gyroscopes, pressure sensors or transducers, displays, optical switching, and fluid ejection. Typically, one or more individual devices are formed on a single die, such as a die formed of an insulating material or a semiconducting material, which can be processed using semiconducting processing techniques, such as photolithography, deposition, or etching.
One type of fluid ejection module includes a die with a plurality of fluid ejectors for ejecting fluid and a flexible printed circuit (“flex circuit”) for communicating signals to the die. The die includes nozzles, ink ejection elements, and electrical contacts. The flex circuit includes leads to connect the electrical contacts of the die with driving circuits, e.g., integrated circuits that generate a drive signal for controlling ink ejection from the nozzles. In some fluid ejection modules, the driving circuits can be part of an integrated circuit chip that is mounted on the flex circuit.
The density of nozzles in the fluid ejection module has increased as fabrication methods improve. For example, MEMS-based devices, frequently fabricated on silicon wafers, are formed in dies with a smaller footprint and with a nozzle density higher than previously. However, the smaller footprint of such devices can reduce the area available for electrical contacts on the die.